SMBC Comics Forum

It doesn't necessarily violate Einstein. Perhaps each child's belief is quantum-entangled with a specific fairy's lifeline, and a fairy's normal alive/dead status is quantum-indeterminate. By stating ("observing") their belief in fairies, the child is causing the collapse of the wave function of the entangled fairy's life. It's not that the statement of belief is causing the fairy to be dead -- it's just that we didn't know whether the fairy was alive or dead.

The physics checks out. The claims of causality violation are spurious and the results are inconclusive. Without further experimentation, the potential of these mythical beings for superluminal communication applications remains unknown. Results also show the ability of physics lovers to enjoy humour targeted almost exclusively towards them without analysing it to death is still dead and buried.

Ummm... I am confused. If kids says that it doesn't believe in fairies and random fairy dies, how would we use it to send message that wouldn't be just a random gibberish?

Oh wait nevermind... I figured a way, while typing in the Username and spambot question... We would have to cage every single fairy and forbid every child to say that sentence and use just one child to say or not the sentence in one second intervals. If he would say that sentence it would be 1, if not it would be zero...

Still it would allow us only to communicate in one way... unless we find another magical creature and another sentence that kills them...

We already have a similar concern due to entanglement, as Araoth says, and it turns out to be a useless effect, as Araoth says. As for disagreement, I'm strongly convinced that macroscopic decoherence is a more likely theory than collapse-plus-no-communication-theorem, mostly thanks to this delightful series: http://lesswrong.com/lw/r5/the_quantum_ ... _sequence/. Just figured it was worth sharing.

I'm beginning to think the actual punchline of Zach's physics comics is all the people who try to put serious thought into them instead of maybe having a chuckle and moving on with their life. It is certainly the part I find most humorous. Those comics usually aren't that funny though, so it is a low bar.

Also, fairies almost certainly aren't real.

FAIRY-KILLER!!!!!!!!!!!!!

Ack, I meant to name Morris as the person with whom I partially agreed.

As for overly-serious discussion following jokes, had you considered that we do it only to make you roll your eyes for our own amusement? (Or maybe there's some crap about taking advantage of every learning/teaching opportunity... some nerdy junk like that which certainly has never provided real-world benefits to anyone.)

http://xkcd.com/660/ XKCD sorta did it

Hate to say this but this is very similar to Terry Pratchetts idea of using Monarchy to communicate via the careful torturing of a small king in order to modulate the signal [monarchy transfers instantaneously on the death of a king]

Why do you hate to say that? It's not a bad thing.

Suppose we can map each fairy to a single child uniquely, and when a child says the word, one of these fairies dies, say randomly.
And suppose we have knowledge of this mapping.

Then we could send a message of k bits by sending k children in space, and the kids assigned to a 1 kill one of their fairies.
And the 0-kids say nothing.

Then we could observe the k sets of fairies on earth and the i-th bit of the message is 1 when a fairy of the i-th set dies.
Otherwise it's zero.

Would that violate Einstein ?

maskedscavenger wrote:Suppose we can map each fairy to a single child uniquely, and when a child says the word, one of these fairies dies, say randomly.
And suppose we have knowledge of this mapping.

Then we could send a message of k bits by sending k children in space, and the kids assigned to a 1 kill one of their fairies.
And the 0-kids say nothing.

Then we could observe the k sets of fairies on earth and the i-th bit of the message is 1 when a fairy of the i-th set dies.
Otherwise it's zero.

Would that violate Einstein ?

The system's fine, what violates relativity is the fact that the death of the fairy occurs instantly after the child speaks his lack of ingenuity. This system could be used as you described to send information instantly to some place many light-years away, effectively transmitting information faster than the speed of light, which according to (special) relativity is impossible. The OP, however, posited that the instant reaction of the fairies might be a consequence of quantum entanglement, which isn't subject to speed-of-light limitations.

On an unrelated note, has anyone else noticed that lately Zach seems hellbent on ruining every children fantasy ever?

To put it in normal people words: it's not going faster than light because technically the information is not traveling anywhere, the people on both ends are just observing the same event happen

Lupk wrote:after the child speaks his lack of ingenuity.

I'm pretty sure you are using ingenuity wrong, I'm not sure what word you meant. I guess you could twist a way to make it work, but it really isn't the same thing as 'belief' at all. Just thought you should know so you can use it properly in the future. It is incredibly annoying when you find out you have been misusing a word for a long time and no one ever bothered to say anything to you. It's like walking around all evening with a big piece of spinach stuckin your front and no one you smile at tells you. Bastards.

Kaharz wrote:

Lupk wrote:after the child speaks his lack of ingenuity.

I'm pretty sure you are using ingenuity wrong, I'm not sure what word you meant. I guess you could twist a way to make it work, but it really isn't the same thing as 'belief' at all. Just thought you should know so you can use it properly in the future. It is incredibly annoying when you find out you have been misusing a word for a long time and no one ever bothered to say anything to you. It's like walking around all evening with a big piece of spinach stuckin your front and no one you smile at tells you. Bastards.

I'm betting he was going for credulity.